Chapter 6: The Birth of the Instrument Section (continued)

But because at that time radar was very hush-hush our use of it could not be widely mentioned. This was one of the problems. That's probably why most people in the RAAF Meteorological Service never heard of our experiments.

In the middle of our experimental flights we began to observed anomalous effects with the subsidence inversion. Boswell said to me one day 'look, the water vapour is a dipole; think about that and you might see what is going on with your signals'. So then we tried that on a radar and we found that the discontinuity of temperature and humidity associated with a subsidence inversion was responsible for the anomalous propagation of the radar reflection.

Radar could have been widely developed for wind-finding during the war. We had it at Darwin when I was Area Meteorologist there and had regular upper winds. Then they brought out the GL3 which was a ten centimetre radar which needed corner reflectors which complicated matters.

I couldn't understand why there was no interest in its development. I complained to Jimmy Twadell without result. There were other factors besides cloudiness which reduced the efficiency of pilot balloon observations by theodolite. Strong jet streams took the balloons to very low angles of elevation so that it could not be seen visually through the haze. Another limitation in the tropics, even with a perfectly clear sky, is the occurrence of a particularly thick salt haze.

Bureau of Meteorology